Modern fire hydrants typically include a bonnet mounted on a standpipe extending out of the ground and connected at a lower end to a fitting and a coupler which is, in turn, connected to the water distribution conveyance piping, also called a water supply main. A valve extends down through the bonnet and standpipe to control the flow of water through the fire hydrant from the water supply main. A valve operating nut extends outward from the bonnet to provide for selective movement of the valve.
One or more discharge nozzle caps are threadingly mounted on sleeves extending outward from the bonnet. Removal of the discharge nozzle caps allows a threaded connection between the sleeve and a fire hose for dispensing water from the fire hydrant when the operating nut is rotated to move the valve to an open position allowing water flow through the hydrant to the fire hose.
Tampering is a constant problem for municipal utilities. Frequently, a discharge nozzle cap is removed from the bonnet and the valve moved to the open position by a non-utility person or fireman to allow water flow from the fire hydrant. While this can be a harmless prank, an open flowing fire hydrant causes a significant decrease in the pressure of the water supply main. This results in an inability to fight fires within the entire section or loop part of the supply main grid since all nearby fire hydrants on that portion of the grid are rendered useless.
A more serious problem is the easy access to the water supply through the fire hydrant for the introduction of harmful elements, such as bacteria, virus, poison etc. It is relatively easy to remove the discharge nozzle cap, introduce a harmful element into the empty interior of the fire hydrant, re-thread the discharge nozzle cap onto the sleeve and then operate the spindle to move the valve to the open position. The flow of water through the water main will then draw the introduced elements into the water supply.
Various tamper resistant devices have been constructed to make it more difficult to unauthorizedly open the fire hydrant and the discharge of water therethrough. Such devices are typically mechanical in nature and fit over the valve operating nut or one or more of the discharge nozzle caps to prevent unauthorized movement of the spindle or cap.
However, such tamper resistant devices have met with limited success. Prior tamper resistant devices have sufficed in their intended design as a deterrent for children whom open fire hydrants to cool off and the average water thief, such as, contractors, pool companies, lawn spraying companies, etc.
However, the prior tamper resistant devices are inadequate for security purposes in the case of the deliberate introduction of contamination or toxic materials into the water supply through a fire hydrant. The wrenches, special tools and mechanical locks or actuators used in such tamper resistant devices are easily defeated by means of ingenious homemade tools, large pipe wrenches, or, in many cases, the actual fire hydrant opening tools acquired from water departments, fire departments, etc., and circulated through a public works department to contractors, plumbers, etc. Further, the only way to determine if a fire hydrant has been tampered with is to visually inspect the hydrant or the tamper resistant device to see if it has been damaged, opened, etc. An individual intent on the deliberate introduction of contaminates into a water system can undetectedly remove a discharge nozzle cap, introduce the contaminates into the hydrant, reinstall the cap, and then open the valve operating nut to cause the contaminates to be drawn into the water supply main. Since there is no discharge of water from the hydrant or resulting pressure loss in the water supply section or grid, this activity is undetectable.
What is needed is an apparatus which detects a fire hydrant operating parameter, such as unauthorized movement of the fire hydrant discharge nozzle cap, during unauthorized removal or attempted removal of the discharge nozzle cap, and then transmits a signal indicating the location of the fire hydrant to a central site, such as a police station, municipal water utility office, etc.
Tamper detection and signaling devices have been constructed for electrical power utilities to detect unauthorized movement of an electric watthour meter from a meter socket. Typically, a tilt switch is mounted in the socket to detect movement of the meter after the meter has been sealingly locked to the socket. However, heretofore there has been no application of tamper detection coupled with automatic remote signaling of a detected tamper event for a fire hydrant.
The present invention is a fire hydrant accessory which provides remote signaling to a central location, such as a water treatment plant system control and data acquisition control room, of a sensed parameter at a fire hydrant location. The sensed parameter can be any one or more of detection of tampering of fire hydrant, water pressure, temperature of the water flowing through the hydrant, temperature of the ambient air surrounding the hydrant, etc. Uniquely, the remote signal from a fire hydrant carries a discrete fire hydrant identification or location indicator which can be correlated to the specific location or street address dispatch of emergency response equipment and personnel, to the fire hydrant for repair, etc.
In one aspect of the invention, the apparatus is a tamper detection apparatus which includes a discharge nozzle cap movement detector mounted on a fire hydrant discharge nozzle cap. The discharge nozzle cap movement detector generates an output upon detecting movement of the discharge nozzle cap relative to the fire hydrant. A transmitter means coupled to the discharge nozzle cap, is responsive to the output of the discharge nozzle cap movement detector for remotely transmitting a tamper detection signal. A control means is mounted in a housing sealingly coupled to the discharge nozzle cap and disposed interiorly within the hydrant. The housing carries the motion detector switch as well as other sensors, such as a pressure sensor or transducer, temperature sensors, condensation and/or moisture sensors, etc. The housing also houses a control means which stores a unique fire hydrant location identification number or code. The transmitter means transmits the identification number or code when transmitting the tamper signal to identify the location of the hydrant. In another aspect of the invention, a fire hydrant includes a housing fluidically coupled to a water supply conduit. A discharge outlet is carried in the housing. A discharge nozzle cap is threadlingly mountable over the discharge outlet to removably open or close the discharge outlet. A discharge nozzle cap movement detector is coupled to the fire hydrant discharge nozzle cap to detect movement of the discharge nozzle cap relative to the fire hydrant. A transmitter is coupled to the discharge nozzle cap and is responsive to the output of the discharge nozzle cap movement detector, for remotely transmitting a tamper detection signal.
In another aspect, the invention is a method for detecting tampering with a fire hydrant. The method comprises the steps of mounting a discharge nozzle cap movement detector in the discharge nozzle cap to detect movement of the discharge nozzle cap relative to the housing and coupling a signal frequency transmitter to the detector so that the transmitter, in response to an output from the motion detector, remotely transmits a tamper signal.
In yet another aspect, the present invention is a method of monitoring a parameter of a fire hydrant. This method comprises the steps of mounting a parameter sensor in the discharge nozzle cap to detect an operating parameter of the interior of the fire hydrant when the discharge nozzle cap is mounted on the discharge outlet of the fire hydrant and coupling a signal frequency transmitter to the sensor so that the transmitter, in response to an output from the sensor, remotely transmits a signal containing data corresponding to the sensed operating parameter as well as the fire hydrant location.
In yet another aspect, the present invention is a method of detecting an operating parameter of a fire hydrant. The method comprises the steps of storing a unique fire hydrant identification in a housing mountable within the discharge nozzle cap, storing the geographical coordinates of the fire hydrant with the unique fire hydrant identification, and providing a transmitter in the housing for transmitting a signal from the housing and fire hydrant to a remote central processor, the signal containing at least the identification of the fire hydrant from which the signal emanated. This method also includes the step of periodically transmitting a check in signal to a remote location to provide operating status, battery status or life, sensor parameter data signal strength, etc.
In yet another aspect, the invention is a discharge nozzle cap for a fire hydrant having a discharge outlet. The discharge nozzle cap includes a body having a first end and a second end. A bore extends from a first end into the body. Threads are formed adjacent the first end of the body for mounting the body on a fluid outlet of a fire hydrant. A housing is fixedly mountable in the bore in the discharge nozzle cap. A sensor is carried by the housing for detecting at least one operating parameter of a fire hydrant in which the housing is mounted. A transmitter is also carried in the housing. The transmitter, when receiving an output signal from the sensor, transmits a remote signal containing data corresponding to the sensor output.
The fire hydrant apparatus of the present invention provides numerous advantages over previously devised fire hydrant parameter detection and/or anti-tampering apparatus. By immediately detecting a tamper event, the water, fire, police departments or other emergency response personnel can be immediately notified to take corrective action. This conserves water since the hydrant is not unauthorizedly open for any lengthy period of time. Any attempts to steal water as well as the loss of system pressure due to a broken water main or open hydrant can also be detected and the location of the hydrant or broken water main immediately identified for quick response.
Additional benefits from the present invention include keeping the hydrants free of debris inserted by individuals which can render the fire hydrant inoperable for use during a fire. Any attempts to open the hydrant to insert hazardous materials into the water supply can also be immediately detected to minimize the range and spread of contamination.
Other benefits include the sensing of pressure changes in the water main by pressure increase detection. Such a pressure increase spike occurs in a section of a water main between two hydrants only when a line is shut down. Real time pressure sensing provided by the present apparatus will immediately reveal any pressure increase event occurring between hydrants indicating a possible deliberate forced introduction of contaminates through a service connection, such as a house or building.